package containers;

//: containers/TypesForSets.java
// Methods necessary to put your own type in a Set.
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.TreeSet;

class SetType {
	int i;

	public SetType(int n) {
		i = n;
	}

	public boolean equals(Object o) {
		return o instanceof SetType && (i == ((SetType)o).i);
	}

	public String toString() {
		return Integer.toString(i);
	}
}

class HashType extends SetType {
	public HashType(int n) {
		super(n);
	}

	public int hashCode() {
		return i;
	}
}

class TreeType extends SetType implements Comparable<TreeType> {
	public TreeType(int n) {
		super(n);
	}

	public int compareTo(TreeType arg) {
		return (arg.i < i ? -1 : (arg.i == i ? 0 : 1));
	}
}

public class TypesForSets {
	static <T> Set<T> fill(Set<T> set, Class<T> type) {
		try {
			for (int i = 0; i < 10; i++)
				set.add(type.getConstructor(int.class).newInstance(i));
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
		return set;
	}

	static <T> void test(Set<T> set, Class<T> type) {
		fill(set, type);
		fill(set, type); // Try to add duplicates
		fill(set, type);
		System.out.println(set);
	}

	public static void main(String[] args) {
		test(new HashSet<HashType>(), HashType.class);
		test(new LinkedHashSet<HashType>(), HashType.class);
		test(new TreeSet<TreeType>(), TreeType.class);
		// Things that don't work:
		test(new HashSet<SetType>(), SetType.class);
		test(new HashSet<TreeType>(), TreeType.class);
		test(new LinkedHashSet<SetType>(), SetType.class);
		test(new LinkedHashSet<TreeType>(), TreeType.class);
		try {
			test(new TreeSet<SetType>(), SetType.class);
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
		try {
			test(new TreeSet<HashType>(), HashType.class);
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
	}
} /* Output: (Sample)
[2, 4, 9, 8, 6, 1, 3, 7, 5, 0]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
[9, 9, 7, 5, 1, 2, 6, 3, 0, 7, 2, 4, 4, 7, 9, 1, 3, 6, 2, 4, 3, 0, 5, 0, 8, 8, 8, 6, 5, 1]
[0, 5, 5, 6, 5, 0, 3, 1, 9, 8, 4, 2, 3, 9, 7, 3, 4, 4, 0, 7, 1, 9, 6, 2, 1, 8, 2, 8, 6, 7]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
java.lang.ClassCastException: SetType cannot be cast to java.lang.Comparable
java.lang.ClassCastException: HashType cannot be cast to java.lang.Comparable
*///:~
